A flue gas desulfurization system and method based on membrane separation technology

Abstract

The application relates to a flue gas desulfurization system and method based on membrane separation technology, which comprises: a flue gas pretreatment unit including a flue gas preheater and a dust remover for increasing the flue gas temperature and removing particulate matters; a membrane separation unit including a membrane support and a membrane assembly for separating sulfur dioxide in the flue gas; a tail gas treatment unit including a tail gas purifier and a condensate treatment device for treating the tail gas and condensate after membrane separation; and a control system including sensors and automatic control devices for real-time monitoring and adjusting system operation parameters. The application efficiently removes sulfur dioxide in the flue gas through the steps of flue gas pretreatment, membrane separation, tail gas treatment and system control, solves the problem of low-temperature flue gas corrosion, improves the desulfurization efficiency and equipment durability. The system has the advantages of high efficiency, corrosion resistance, energy saving and environmental protection, and automatic control, and is suitable for flue gas treatment in coal-fired power plants, steel smelting, petrochemical industries and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of flue gas desulfurization technology, in particular to a flue gas desulfurization system and method based on membrane separation technology. BACKGROUND

[0002] Traditional flue gas desulfurization technologies (such as wet desulfurization) have problems such as high energy consumption, complex wastewater treatment, and equipment corrosion. Membrane separation technology has advantages such as high efficiency, energy saving, and environmental protection, but is easily affected by corrosion in low-temperature flue gas treatment. Therefore, it is of great significance to develop a flue gas desulfurization system and method based on membrane separation technology that is efficient and corrosion-resistant. SUMMARY

[0003] The purpose of the present application is to provide a flue gas desulfurization system and method based on membrane separation technology, which solves the problem of low-temperature flue gas corrosion and improves desulfurization efficiency and equipment durability.

[0004] The flue gas desulfurization system based on membrane separation technology provided by the present application adopts the following technical solution:

[0005] A flue gas desulfurization system based on membrane separation technology, the device comprises:

[0006] A flue gas pretreatment unit, including a flue gas preheater and a dust collector, for increasing the temperature of the flue gas and removing particulate matter;

[0007] A membrane separation unit, including a membrane support and a membrane assembly, for separating sulfur dioxide in the flue gas;

[0008] A tail gas treatment unit, including a tail gas purifier and a condensate treatment device, for treating tail gas and condensate after membrane separation; and

[0009] A control system, including sensors and automatic control devices, for real-time monitoring and adjusting system operating parameters.

[0010] As a preferred technical solution of the present application, the flue gas preheater comprises a heating sleeve in the shape of a cylinder and a heating assembly arranged in the heating sleeve, one end of the heating sleeve is connected with a flue gas inlet, the other end is connected with the dust collector, and an installation cavity for installing the membrane separation unit is arranged in the heating sleeve.

[0011] As a preferred technical solution of the present application, the dust collector comprises an air inlet chamber in communication with the internal space of the heating sleeve and a filter chamber in communication with the air inlet chamber, a detachable filter screen is arranged in the filter chamber, an air inlet is formed on the side wall of the air inlet chamber, and an air outlet for communicating with the air inlet is formed on the end of the inner wall of the heating sleeve.

[0012] The inner wall of the heating jacket is provided with a mounting ring, the dust remover is elastically connected with the mounting ring through a plurality of connecting springs, one end of the air inlet bin away from the filter bin is sealingly connected with the inner wall of the heating jacket, and the connection area of the air inlet and the air outlet is adjustable.

[0013] The film support comprises a connecting support connected to the inner wall of the heating jacket and a plurality of groups of film mounting racks connected to the connecting support, the connecting support is sealingly connected with the inner wall of the heating jacket, and the film assembly is connected to the film mounting rack.

[0014] The connecting support is provided in a cylindrical structure with a cross section matched with the shape of the inner wall of the heating jacket, the film mounting rack is arranged in the connecting support, the side wall of the connecting support is provided with a mounting opening opposite to the position of the film mounting rack, the film assembly is mounted to the film mounting rack through the mounting opening, and one end of the connecting support is open and faces the dust remover, and the other end is open and away from the dust remover.

[0015] The tail gas purifier is connected to one end of the connecting support away from the dust remover, and is arranged outside the mounting cavity, the tail gas purifier is provided with a tail gas adsorption and purification module inside, and is provided with a purified gas outlet outside.

[0016] The condensate treatment device is connected to the outside of the tail gas purifier or the side away from the connecting support, and is in communication with the inside of the tail gas purifier.

[0017] The sensor comprises a temperature sensor for monitoring the temperature of flue gas and a pressure sensor for monitoring the system pressure.

[0018] The flue gas desulfurization method based on the membrane separation technology provided by the application adopts the following technical scheme:

[0019] A flue gas desulfurization method based on the membrane separation technology comprises the following steps:

[0020] S1: flue gas pretreatment, the flue gas temperature is increased through a flue gas preheater to prevent the formation of acidic condensate, and particulate matter is removed through a dust remover;

[0021] S2: membrane separation, the pretreated flue gas is introduced into a membrane separation unit, and sulfur dioxide is separated by using a film assembly;

[0022] S3: tail gas treatment, the tail gas after the membrane separation is introduced into a tail gas purifier to remove residual acidic substances, and a condensate treatment device is used to collect and treat the condensate;

[0023] System control, through the control system real-time monitoring and adjusting the temperature, pressure parameters in S1-S3 steps, ensure the system efficient operation.

[0024] In summary, the present application includes at least one of the following beneficial technical effects:

[0025] 1. The present application adopts membrane separation technology to efficiently remove sulfur dioxide in flue gas, with high desulfurization efficiency.

[0026] 2. The membrane module of the present application uses corrosion-resistant materials and anti-corrosion coating, effectively solving the problem of low-temperature flue gas corrosion, and improving the durability of the equipment.

[0027] 3. The present application realizes automatic operation through the control system, improves the operation convenience and system stability.

[0028] 4. In the present application, the dust collector, membrane module and membrane support are placed in the installation cavity formed by the heating jacket, making the structure of the whole system more compact, small in size and space occupation, facilitating the movement and installation of the equipment.

[0029] 5. In the present application, the flue gas preheater is set as a hollow cylindrical shape, and when the flue gas passes through the heating jacket, it can better contact with the heating assembly, thereby keeping the flue gas at a relatively high temperature, facilitating desulfurization.

[0030] 6. In the present application, the membrane separation unit is arranged in the heating jacket, and the membrane separation unit is heat-insulated by the heating jacket to prevent the preheated flue gas from cooling too much during transportation and affecting normal desulfurization, especially when the system is applied in cold outdoor weather, thereby ensuring the desulfurization efficiency of the whole system.

[0031] 7. In the present application, the heating jacket and the dust collector are elastically connected through the connecting spring, when the flue gas pressure transmitted by the heating jacket to the dust collector is small, the dust collector is moved to the outside of the installation cavity under the action of its own gravity or the pulling force of the connecting spring, so that the communication area of the exhaust port and the gas inlet port is small, which can ensure the high flow rate of the flue gas and improve the efficiency of flue gas dust removal and subsequent desulfurization; when the flue gas pressure transmitted by the heating jacket to the dust collector is large, the gas pressure will push the dust collector to move to the outside of the installation cavity, so that the exhaust port and the gas inlet port are fully connected, improving the flue gas discharge efficiency and desulfurization treatment efficiency. The system can automatically adjust the exhaust volume according to the change of the flue gas pressure. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 is a flow structure schematic diagram of an embodiment of the present application;

[0033] Figure 2 is a schematic diagram of the external structure of the whole system of an embodiment of the present application;

[0034] Figure 3is a schematic diagram of the internal structure of the whole system of the embodiment of the present application;

[0035] Figure 4 is a schematic diagram of the connection structure of the flue gas preheater and the dust collector in the embodiment of the present application;

[0036] Figure 5 is a schematic diagram of the connection structure of the flue gas preheater and the membrane support in the embodiment of the present application;

[0037] Figure 6 is a schematic diagram of the connection structure of the tail gas purifier and the condensate treatment device in the embodiment of the present application;

[0038] In the figure, 1, flue gas preheater; 11, heating jacket; 12, heating assembly; 13, flue gas inlet; 14, mounting cavity; 15, exhaust port; 16, mounting ring; 2, dust collector; 21, air inlet chamber; 22, filter chamber; 23, filter screen; 24, air inlet; 25, connecting spring; 3, membrane support; 31, connecting support; 32, membrane mounting frame; 33, mounting port; 4, membrane assembly; 5, tail gas purifier; 51, tail gas adsorption and purification module; 52, purified gas outlet; 6, condensate treatment device; 7, automatic control device. DETAILED DESCRIPTION

[0039] The following will be described in detail in combination with the accompanying Figure 1 - the accompanying Figure 6 The present application will be further described in detail.

[0040] The embodiments of the present application will be described in detail below, and examples of the embodiments are shown in the accompanying drawings, in which the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the accompanying drawings are exemplary and are intended to explain the present application, and cannot be understood as a limitation of the present application.

[0041] Embodiment: The present application proposes a flue gas desulfurization system based on membrane separation technology, which is suitable for flue gas treatment in coal-fired power plants, steel smelting, petroleum chemical industry and other industries, and the system comprises a flue gas preheater, a dust collector, a membrane support, a membrane assembly, a tail gas purifier, a condensate treatment device and an automatic control device. Figures 1-6The system comprises a flue gas pretreatment unit, a membrane separation unit, a tail gas treatment unit and a control system. The flue gas pretreatment unit comprises a flue gas preheater 1 and a dust remover 2. The flue gas preheater 1 is connected to a flue gas source and is used to increase the temperature of the flue gas to prevent the formation of acidic condensate. The dust remover 2 is connected to the flue gas preheater 1 and is used to remove particulate matter from the flue gas. The membrane separation unit comprises a membrane support 3 and a membrane assembly 4. The membrane assembly 4 is installed in groups on the membrane support 3. The membrane support 3 is connected to the flue gas preheater 1 or the dust remover 2. The membrane assembly 4 is used to separate sulfur dioxide from the flue gas. The tail gas treatment unit comprises a tail gas purifier 5 and a condensate treatment device 6. The tail gas purifier 5 is connected to the outlet of the membrane separation unit and is used to treat the tail gas after membrane separation to remove harmful substances. The condensate treatment device 6 is installed in the tail gas purifier 5 and is used to treat the condensate formed during the cooling of the tail gas. The control system comprises sensors and an automatic control device 7. The sensors comprise temperature sensors and pressure sensors. The temperature sensors are used to monitor the temperature of the flue gas at each stage. The pressure sensors are used to monitor the pressure of the flue gas at each stage. This facilitates the automatic control device 7 to adjust the operating parameters of each stage of the system in real time based on the monitoring data of the sensors.

[0042] With reference to Figure 2 and 3 The flue gas preheater 1 comprises a heating jacket 11 and a heating assembly 12. The heating jacket 11 is cylindrical and can be a circular cylinder or a square cylinder. In this embodiment, a circular cylinder is used. The heating jacket 11 comprises two layers of cylindrical sleeves. A flue gas passing layer is provided between the two layers of sleeves. The flue gas passing layer is also cylindrical. The two ends of the heating jacket 11 are sealed by annular plates. The heating jacket 11 can be placed horizontally or vertically, depending on actual needs. In this embodiment, the heating jacket 11 is placed vertically.

[0043] The heating assembly 12 is arranged in the inner layer of the heating jacket 11. The heating assembly 12 can be electric heating wires or electric heating rods, which are uniformly arranged on the inner layer of the heating jacket 11 to heat the flue gas.

[0044] In this embodiment, a plurality of flue gas inlet ports 13 are uniformly arranged at the lower end of the heating jacket 11 to be connected to a flue gas source through a pipeline. The upper end of the heating jacket 11 is connected to the dust remover 2. A cylindrical installation cavity 14 is formed in the heating jacket 11. The installation cavity 14 is used to install the membrane separation unit.

[0045] For example, a plurality of exhaust ports 15 are circumferentially arranged on the upper part of the inner layer of the heating jacket 11. The exhaust ports 15 are used to discharge the preheated flue gas outwardly and are connected to the internal space of the dust remover 2. In this embodiment, the exhaust ports 15 are long strips with the length direction being the vertical direction.

[0046] With reference to Figure 4The two mounting rings 16 on the side wall of the heating jacket 11 in the installation cavity 14 are arranged oppositely in up and down directions, and the height of the mounting rings 16 is lower than the exhaust port 15. The dust collector 2 is installed on the upper side of the upper mounting ring 16, and the membrane separation unit is installed on the lower side of the lower mounting ring 16. The fan for blowing air to the membrane separation unit is installed between the two mounting rings 16 to promote the flow of flue gas.

[0047] The dust collector 2 includes an air inlet chamber 21 and a filter chamber 22, and both parts are provided with an outer shell and an internal space in communication. The air inlet chamber 21 is in a cylindrical shape, and the top end extends out of the installation cavity 14 and is sealed. The outer side wall of the air inlet chamber 21 is tightly attached to the side wall of the installation cavity 14 and is sealed. A circle of air inlets 24 is formed on the side wall of the air inlet chamber 21, and the air inlets 24 correspond to the exhaust ports 15 one by one. The air inlets 24 are also arranged in a long strip shape with the length direction being the up and down direction. The air inlet chamber 21 is in communication with the internal interlayer space of the heating jacket 11 through the air inlets 24. The filter chamber 22 is connected to the side of the air inlet chamber 21 extending into the installation cavity 14. The filter chamber 22 is connected to the air inlet chamber 21 through a flange plate. An exhaust passage is arranged on the bottom plate of the filter chamber 22. A detachable filter screen 23 is installed in the filter chamber 22 to filter particulate matter.

[0048] In some embodiments, the dust collector 2 and the mounting ring 16 are elastically connected through a plurality of connecting springs 25. Specifically, the plurality of connecting springs 25 are axially parallel and uniformly distributed. The upper end of the connecting spring 25 is connected to the bottom plate of the filter chamber 22, and the lower end of the connecting spring 25 is connected to the upper mounting ring 16. The relative position of the dust collector 2 and the heating jacket 11 can be adjusted through the connecting spring 25, so that the connection area of the air inlet 24 and the exhaust port 15 can be adjusted. When the flue gas pressure transmitted by the heating jacket 11 to the dust collector 2 is small, the lower part of the exhaust port 15 and the upper part of the air inlet 24 are connected under the action of the gravity of the dust collector 2, and the connection area is small, which can ensure a high flow rate of flue gas and improve the efficiency of dust removal and subsequent desulfurization of flue gas. When the flue gas pressure transmitted by the heating jacket to the dust collector is large, the pressure will push the dust collector 2 to move upward, so that the connection area of the exhaust port 15 and the air inlet 24 increases and is fully connected, which increases the flow of flue gas and improves the efficiency of flue gas emission and desulfurization treatment.

[0049] When the filter screen 23 is disassembled and replaced, the dust collector 2 can be pulled out of the installation cavity 14.

[0050] Referring to Figure 5 The membrane support 3 includes a connecting support 31 and a membrane mounting rack 32. The connecting support 31 is connected to the inner wall of the heating jacket 11. A plurality of groups of membrane mounting racks 32 are connected along the axial direction of the connecting support 31, and a plurality of groups of membrane assemblies 4 can be installed.

[0051] Exemplary, the connecting bracket 31 is provided as a cylindrical structure with a cross section that matches the shape of the inner wall of the heating jacket 11, so that the connecting bracket 31 is sealingly connected with the inner wall of the heating jacket 11. The connecting bracket 31 is open at both the upper and lower ends for the entry and exit of flue gas. The upper end of the connecting bracket 31 is connected to the lower mounting ring 16 by bolts. A plurality of membrane mounting racks 32 are arranged inside the connecting bracket 31 and parallel to the upper and lower end faces of the connecting bracket 31. In this embodiment, the membrane mounting rack 32 is a clamping plate with a clamping space in the middle. The membrane mounting rack 32 is provided with through grooves on both the upper and lower sides. The connecting bracket 31 is provided with mounting ports 33 on the side wall opposite the positions of the membrane mounting racks 32. The clamping space of the membrane mounting rack 32 is provided with an opening on the side opposite the mounting port 33, for the insertion of the membrane module 4. The membrane module 4 is mounted to the membrane mounting rack 32 through the mounting port 33.

[0052] In this embodiment, the membrane module 4 is made of corrosion-resistant material and has a corrosion-resistant coating on the surface, such as stainless steel or ceramic membrane. The membrane module 4 is provided with a sulfur dioxide separation outlet that is connected to the outside of the heating jacket 11. The separated sulfur dioxide can be recycled or sent to a treatment device for treatment. The flue gas treated by the dust collector 2 enters the membrane separation unit and is discharged after the sulfur dioxide is separated by the membrane module 4, and enters the tail gas treatment unit.

[0053] Referring to Figure 6 , the tail gas purifier 5 is connected to the lower end of the connecting bracket 31, and the lower end of the connecting bracket 31 extends out of the heating jacket 11, so that the tail gas purifier 5 is arranged outside the mounting cavity 14. The tail gas purifier 5 is provided with a tail gas adsorption and purification module 51 inside, which is arranged as an activated carbon adsorption or chemical absorption device. The tail gas purifier 5 is provided with a purified gas outlet 52 outside. In this embodiment, the bottom plate of the tail gas purifier 5 is provided as a structure with a center that is high and edges that gradually decrease. The condensed liquid is collected through the low-lying part of the edge of the bottom plate. The purified gas outlet 52 is arranged at the highest point of the bottom plate of the tail gas purifier 5, which can effectively prevent the condensed liquid from being discharged with the tail gas from the purified gas outlet 52.

[0054] The condensed liquid treatment device 6 is installed outside or below the tail gas purifier 5. In this embodiment, the condensed liquid treatment device 6 is arranged as an annular structure and is coaxially installed on the bottom plate of the tail gas purifier 5. The condensed liquid treatment device leaves a position where the purified gas outlet 52 is located in the middle and is in communication with the inside of the tail gas purifier 5 through the bottom plate of the tail gas purifier 5. The condensed liquid collected on the bottom plate of the tail gas purifier 5 can enter the condensed liquid treatment device 6 for treatment.

[0055] The temperature sensor and the pressure sensor are connected to the automatic control device 7 through a line, and transmit monitoring data to the automatic control device 7. The automatic control device 7 is connected to the flue gas preheater 1, the membrane assembly 4 and the tail gas purifier 5 through a line, and controls the flue gas preheater 1, the membrane assembly 4 and the tail gas purifier 5. In the embodiment, the automatic control device 7 is installed outside the heating jacket 11.

[0056] The application also provides a flue gas desulfurization method based on membrane separation technology, which is combined with the above-mentioned flue gas preheater, the membrane assembly and the tail gas purifier. Figure 1 The steps of the method are as follows:

[0057] S1: flue gas pretreatment, the flue gas enters the heating jacket 11 through the flue gas inlet 13, and the temperature of the flue gas is increased through the heating of the heating assembly 12 to prevent the formation of acidic condensate. The flue gas enters the dust collector 2 through the gas inlet 24, and the solid particles in the flue gas are removed by the filter screen 23.

[0058] S2: membrane separation, the pretreated flue gas is transported into the membrane separation unit through a fan, and sulfur dioxide is separated by the membrane assembly 4. The separated sulfur dioxide is discharged through the sulfur dioxide separation outlet, and the tail gas enters the tail gas treatment link.

[0059] S3: tail gas treatment, the tail gas after membrane separation is introduced into the tail gas purifier 5, and the tail gas is cooled to form condensate again. The acidic substances are absorbed by the tail gas adsorption and purification module 51, the condensate is collected and treated by the condensate treatment device 6, and the treated tail gas is discharged through the purified gas outlet 52.

[0060] System control, the temperature and pressure parameters of the flue gas preheater 1, the dust collector 2 and the tail gas purifier 5 in S1-S3 are monitored and adjusted in real time through the control system, to ensure efficient operation of the system.

[0061] The embodiments of the specific embodiment are the preferred embodiments of the application, and are not limited to the protection scope of the application. The same parts are indicated by the same reference numerals. Therefore, equivalent changes made according to the structure, shape and principle of the application should be covered by the protection scope of the application.

Claims

1. A flue gas desulfurization system based on membrane separation technology, characterized by, The system comprises: a flue gas pretreatment unit comprising a flue gas preheater (1) and a dust remover (2) for increasing the temperature of the flue gas and removing particulate matter; a membrane separation unit comprising a membrane support (3) and a membrane assembly (4) for separating sulfur dioxide in the flue gas; a tail gas treatment unit comprising a tail gas purifier (5) and a condensate treatment device (6) for treating the tail gas after membrane separation and condensate; and a control system comprising sensors and automatic control devices (7) for real-time monitoring and adjusting system operating parameters. The flue gas preheater (1) comprises a heating sleeve (11) in the shape of a cylinder and a heating assembly (12) arranged in the heating sleeve (11), one end of the heating sleeve (11) is connected with a flue gas inlet (13), the other end is connected with the dust remover (2), and the heating sleeve (11) is provided with a mounting cavity (14) for mounting the membrane separation unit. The dust remover (2) comprises an air inlet bin (21) in communication with the internal space of the heating sleeve (11) and a filter bin (22) in communication with the air inlet bin (21), a detachable filter screen (23) is arranged in the filter bin (22), an air inlet (24) is formed in the side wall of the air inlet bin (21), and an exhaust port (15) for communicating with the air inlet (24) is formed in the end of the inner wall of the heating sleeve (11). The inner wall of the heating sleeve (11) is provided with a mounting ring (16), the dust remover (2) and the mounting ring (16) are elastically connected through a plurality of connecting springs (25), one end of the air inlet bin (21) away from the filter bin (22) is sealingly connected with the inner wall of the heating sleeve (11), and the connection area of the air inlet (24) and the exhaust port (15) is adjustable. The membrane support (3) comprises a connecting support (31) connected to the inner wall of the heating sleeve (11) and a plurality of groups of membrane mounting racks (32) connected to the connecting support (31), the connecting support (31) is sealingly connected with the inner wall of the heating sleeve (11), and the membrane assembly (4) is connected to the membrane mounting rack (32).

2. A flue gas desulphurization system based on membrane separation technology as claimed in claim 1, wherein, The connecting support (31) is provided in the form of a cylindrical structure with a cross section matching the shape of the inner wall of the heating sleeve (11), the membrane mounting rack (32) is arranged inside the connecting support (31), the side wall of the connecting support (31) is provided with a mounting port (33) opposite the position of the membrane mounting rack (32), the membrane assembly (4) is mounted to the membrane mounting rack (32) through the mounting port (33), one end of the connecting support (31) is open and faces the dust remover (2), and the other end is open and away from the dust remover (2).

3. A flue gas desulphurization system based on membrane separation technology as claimed in claim 2, wherein, The tail gas purifier (5) is connected to one end of the connecting support (31) away from the dust remover (2), and the tail gas purifier (5) is arranged outside the mounting cavity (14), the tail gas purifier (5) is provided with a tail gas adsorption and purification module (51) inside, and a purified gas outlet (52) is arranged outside the tail gas purifier (5).

4. A flue gas desulphurization system based on membrane separation technology as claimed in claim 3, wherein, The condensate treatment device (6) is connected to the outside of the tail gas purifier (5) or one side away from the connecting support (31), and the condensate treatment device (6) is in communication with the inside of the tail gas purifier (5).

5. A flue gas desulphurization system based on membrane separation technology as claimed in any one of claims 1 to 4, wherein, The sensors comprise a temperature sensor for monitoring the temperature of the flue gas and a pressure sensor for monitoring the pressure of the system.

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